Table 2.

Case analysis of seven patients with discordant results between IHC and PCR

Patient ID	Stage	Pathology	Tumor site	IHC interpretation	Absent protein of IHC	MSI-PCR	MSI-NGS	TMB (muts/Mb)	MMR relative alterations	Review or Retest of IHC
14,167	IV	Adenocarcinoma	Ascending colon	pMMR	None	MSI-H	MSS	7.1		Not enough tissue
31,713	IV	Adenocarcinoma	Rectum	dMMR	MLH1 and PMS2	MSS	MSS	20.2	MLH1 R265C and BRAF V600E	Not enough tissue
12,563	IV	Signet ring cell	Rectum	dMMR	PMS2	MSS	MSS	1.1		Retest as pMMR
11,640	IV	Adenocarcinoma	Ileocecal junction	dMMR	PMS2	MSS	MSS	7.1		Review as Misinterpretation
12,873	II	Adenocarcinoma	Ascending colon	dMMR	PMS2	MSS	MSS	280.9	PMS2 p.R563* and POLE p.P286R	Not enough tissue
12,880	II	Adenocarcinoma	Rectum	dMMR	MSH6	MSS	MSS	3.2		Retest as pMMR
15,706	IV	Adenocarcinoma	Descending colon	dMMR	MSH6	MSS	MSS	8.1		Retest as pMMR